JP2000271602A - Manufacture of patterned steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a patterned steel sheet whose surface is smooth and excellent in design. SOLUTION: After executing cold rolling by which the projecting and recessing part having the difference in level of 0.5-1.0% of the thickness of the sheet is transferred to the surface of a steel sheet using a work roll that a projecting and recessing pattern is applied on the roll surface, cold finishing rolling is executed at a draft of 30-90% using the work roll having 0.02-0.25 μm mean roughness Ra of the roll surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a patterned steel sheet having excellent design.

[0002]

2. Description of the Related Art In general, as a method for producing a patterned steel sheet having a pattern or pattern on the surface of a steel sheet, a pattern or pattern is digged into a work roll used in a final pass (or a final stand) of cold rolling. A method of transferring a pattern or a pattern by rolling a steel sheet by a work roll and a method of directly etching a steel sheet are known.

[0003]

SUMMARY OF THE INVENTION A method of transferring a pattern or pattern to a steel sheet in a final pass (or a final stand) of cold rolling using a work roll into which the pattern or pattern is laid, or directly etching a steel sheet. According to the method, irregularities always occur in a portion corresponding to a pattern or a contour of the pattern on the surface of the steel sheet. For example, the unevenness easily becomes a hotbed of various bacteria in sanitary goods and the like, and the surface of the steel sheet has been required to be smooth.

[0004] Therefore, in order to reduce the above-mentioned irregularities, if the rolling reduction is increased by finish rolling after cold rolling for transferring the irregularities, the pattern or pattern on the steel sheet surface will be distorted, and the pattern will be distorted. However, there was a problem that the desired design was not obtained. An object of the present invention is to provide a method for producing a patterned steel sheet having a smooth surface and excellent design, which solves the above problems.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems, and as a result, in order to manufacture a patterned steel sheet having a smooth surface and excellent design, a finish cold finish is required. The present inventors have found that the step height of the unevenness before rolling and the surface roughness and rolling reduction of the work roll in performing the finish cold rolling are important, and completed the present invention.

That is, the present invention relates to a method for producing a patterned steel sheet which is subjected to cold rolling to impart a pattern to the surface of the steel sheet. Cold rolling is performed to transfer irregularities having a step of 0.5 to 1.0%, and then, using a work roll having an average surface roughness of the roll Ra: 0.02 to 0.25 μm, a rolling reduction of 30 to 90% is applied. This is a method for producing a patterned steel sheet, comprising performing cold rolling.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The important points of the present invention are (1) the step of unevenness transferred to the steel sheet surface by cold rolling, (2) the surface roughness of a work roll used for finish cold rolling, and (3) There are three points of reduction in finish cold rolling, and the reasons for these limitations will be described below. Here, the patterned steel sheet excellent in design of the present invention means that the pattern of the steel sheet has no distortion and the pattern is clear.

[0008] The unevenness of the surface of the steel plate: 0.5 to 1.0 of the plate thickness
% Using a work roll with an uneven pattern, cold rolling is performed to make the unevenness level of the steel sheet surface 0.5 to 1.0% of the sheet thickness. If the unevenness of the surface of the steel sheet is less than 0.5% of the sheet thickness, the pattern when subjected to finish cold rolling becomes unclear, and the design is reduced. On the other hand, when the unevenness exceeds 1.0% of the sheet thickness, smoothing by finish cold rolling becomes difficult, and unevenness remains on the surface of the steel sheet after finish cold rolling, or the pattern is distorted and the design is distorted. Is reduced. For this reason, the unevenness of the surface of the steel sheet is set to 0.5 to 1.0% of the sheet thickness. Where the thickness
The unevenness of the surface of the steel sheet, which is 0.5 to 1.0%, is imparted by performing cold rolling at a predetermined rolling reduction and / or a predetermined rolling load using a work roll provided with a concave portion having a predetermined depth. You can do it.

[0010] Cold rolling using a work roll with an uneven pattern is desirably performed in one pass in reverse rolling and one stand in tandem rolling in view of the sharpness of the pattern of the steel sheet. . The uneven pattern is usually applied to the surface of the work roll by known machining or etching. The etching process is more excellent in workability, so that the degree of freedom of the pattern can be obtained. Here, the etching process means a normal chemical etching process, for example, by attaching an acid-insoluble film having a desired pattern to a work roll surface,
This is a method of imparting an uneven pattern to the surface of the work roll by performing elution treatment of a portion where the film is not attached with an acid.

[0010] Next, the finish cold rolling to be performed is performed in one or more stands by a tanden mill or one or more passes by a reverse mill after cold rolling for imparting an uneven pattern to the surface of the steel sheet. Average roughness Ra of work roll in finish cold rolling: 0.02 to 0.25
The surface roughness of the work roll used for the cold finish rolling of μm is one of the important factors. When the average roughness Ra of the work roll in the finish cold rolling is set to less than 0.02 μm, slip occurs or the surface polishing treatment of the work roll is costly and not economical. On the other hand, when the average roughness Ra of the work roll in the finish cold rolling exceeds 0.25 μm, the surface roughness of the work roll is transferred to the steel sheet, the pattern on the surface of the steel sheet becomes unclear, and the design is deteriorated. For this reason, the work roll surface roughness Ra
0.02 to 0.25 μm.

The rolling reduction of the finish cold rolling: 30 to 90% The rolling reduction of the finish cold rolling smoothes the unevenness of the steel sheet surface imparted by the cold rolling, makes the pattern of the steel sheet surface clear, and It is an important factor in ensuring that there is no distortion. When the rolling reduction of the finish cold rolling is less than 30%, even if the surface of the steel sheet is provided with irregularities of 0.5 to 1.0% of the thickness, the smoothness of the steel sheet surface after the finish cold rolling is not obtained, and the irregularities remain. . On the other hand, when the rolling reduction in the finish cold rolling exceeds 90%, the pattern on the surface of the steel sheet becomes unclear, and the pattern on the surface of the steel sheet is distorted to deteriorate the design. For this reason, the rolling reduction of the finish cold rolling is set to 30 to 90%. 40% reduction in finish cold rolling
In the case where the ratio exceeds 2, from the viewpoint of suppressing the distortion of the pattern on the surface of the steel sheet, it is preferable that the reverse mill is performed in two passes or more, and the tandem mill is performed in two stands or more.

Further, the present invention is preferably applied to a stainless steel plate used for sanitary articles and the like.

[0013]

EXAMPLE 1 A rectangular recess having a side length of 3.0 mm and a depth of 200 μm shown in FIG. 1 was formed by etching on the entire rolled portion of the work roll surface of a reverse mill in the roll axis direction. The gap was 3.0 mm, and the gap was 3.0 mm in the circumferential direction of the roll. The work roll is used to reduce the rolling reduction of the fifth pass of the reverse mill by 0.8% (or the rolling pressure).
0.04ton / mm) and a 1.0% step (20 mm
.mu.m). Also,
The sixth to ninth passes of the reverse mill were performed using a work roll having an average roughness Ra of 0.10 μm and a reduction of 50%.
Was subjected to cold rolling to finish the sheet to a thickness of 1.00 mm. FIG. 3 (a) shows a schematic view of the surface of the steel sheet after the finish cold rolling, and FIG. 3 (b) shows a sectional view thereof. FIG. 3 (a) shows that the cold rolling method of the present invention has no distortion in the rectangular pattern. FIG.
From (b), it can be seen that the unevenness step shown in FIG. 2 (b) before the finish cold rolling is eliminated, and the steel sheet surface is smoothed. Further, as a comparative example, a work roll having the same diameter as that of the invention and having the same concave portion was rolled with the same number of passes of the reverse mill using a work roll of the same diameter, and the rolling reduction was 4.0%, mm), a pattern having a 5.0% step (100 μm) with a plate thickness of 2.00 mm was provided. Thereafter, in the same reverse mill pass as in the invention example, using a work roll having an average roughness Ra: 0.10 μm, the same finish cold-rolling as in the invention example was performed at a reduction rate of 50% to finish the sheet thickness to 1.00 mm. Was. FIG. 4 (a) shows a schematic view of the surface after the finish cold rolling, and FIG. 4 (b) shows a sectional view thereof. From this, it can be seen that in the comparative example, as shown in FIG. 4 (a), the pattern is distorted and the design quality is reduced. Further, in the comparative example, as shown in FIG. 4 (b), the unevenness of the surface of the steel sheet shown in FIG. 2 (b) before the finish cold rolling was eliminated and the steel sheet surface was smoothed. Inside, the boundary which was uneven before the finish cold rolling is inclined. The boundary inside the steel sheet is a problem because it is a difference in texture between the rolling direction and the anti-rolling direction. Example 2 The work rolls used in the tandem mill and the work rolls used in the reverse mill were subjected to different etching times, and the depth of the rectangular recess having the same side length as in Example 1 shown in FIG. Changed. And
Using a five-stand tandem mill and a reverse mill, the stainless steel plate was subjected to cold rolling as shown in Table 1 to obtain a patterned steel plate. That is, in rolling No. 13 using a five-stand tandem mill, the work rolls provided with the pattern by etching were incorporated into the third stand of the tandem mill, and the work rolls were added to the fourth and fifth stands of the tandem mill. Work rolls having the average roughness shown in Table 1 were assembled, and cold rolling was performed to provide uneven steps shown in Table 1, and then finish cold rolling was performed at the rolling reduction shown in Table 1.
In rolling No. 11 using a five-stand tandem mill, a work roll provided with a pattern by etching was incorporated into a fourth stand, and a fifth roll of a tandem mill was used.
A work roll having an average roughness shown in Table 1 was incorporated into the stand, and subjected to cold rolling for imparting unevenness shown in Table 1, followed by finish cold rolling at a rolling reduction shown in Table 1. did. On the other hand, in the reverse mill, the unevenness shown in Table 1 is applied to the stainless steel plate in one pass except for the final pass by using a work roll provided with a pattern by etching, and thereafter, the work roll shown in Table 1 is used. Finish cold rolling was performed using a work roll having the average roughness, the number of passes, and the rolling reduction.

The results of smoothness and design obtained by performing cold rolling are shown in Table 1. Here, the smoothness and design of the obtained steel sheet were evaluated as follows. The smoothness was measured by measuring the surface roughness of the steel sheet. The smoothness was evaluated as ○ when the ten-point average roughness Rz was less than 0.25 μm, and as × when the ten-point average roughness Rz was 0.25 μm or more. The design was evaluated by both the sharpness of the pattern on the steel sheet surface and the distortion of the pattern on the steel sheet surface. The sharpness of the pattern was visually evaluated relative to the limit sample of the same pattern obtained in the past (a steel plate with a sharpness that was just above the limit). The evaluation of the distortion of the pattern on the surface of the steel sheet was evaluated by calculating the distortion value (the average value of the length up to the tip of the convex portion shown in FIG. 4 (a) and the maximum length of the concave portion: (a + b ) / 2 was given by the etching process shown in FIG. 1 and divided by the length c of a piece of the work roll rectangle c: 3.0 mm. The overall evaluation of the designability was evaluated as ○ when both the evaluation of the sharpness of the pattern and the evaluation of the distortion of the pattern were ○, and when either or both were ×,
And

[0015]

[Table 1]

From these results, it can be seen that the present invention has a smoother steel sheet surface and better design than the comparative example.

[0017]

According to the present invention, a patterned steel sheet having a smooth surface and excellent design can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a work roll provided with a concavo-convex pattern used in the present invention.

FIG. 2 is a schematic view showing unevenness of a steel sheet rolled using the work roll shown in FIG.

FIG. 3 is a schematic view showing a concavo-convex pattern of a steel sheet subjected to finish cold rolling by the cold rolling method of the present invention.

FIG. 4 is a schematic view showing a concavo-convex pattern of a steel sheet subjected to finish cold rolling by a cold rolling method of a comparative example.

[Explanation of symbols]

 1 work roll 2 steel plate

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E002 AD05 AD06 AD10 BA01 BB09 CB09 4E016 AA03 BA01 CA04 CA09 DA13

Claims (1)

[Claims] 1. A method for producing a patterned steel sheet, in which a pattern is imparted to the surface of a steel sheet by performing cold rolling, using a work roll having an uneven pattern on the surface of the roll, using a work roll having a thickness of 0.5 to 1.0. % Of the roll surface after cold rolling to transfer unevenness having a step of 0.1% to 0.02 to 0.25 μm
A method for producing a patterned steel sheet, comprising performing finish cold rolling at a rolling reduction of 30 to 90% using the work roll described above.